Firing device for a point detonating fuze



lo 32 y ss INVENTUM. S. E. WHEATLEY j; .LBAKER RM qjmry ited tas Baker, College Park, Md., of America as represented Bethesda, and Kenneth L. assignors to the United States by the Secretary of the Navy Application October 15, 1951, Serial No. 251,432 1 Claim. (Cl. 102-80) (Granted under Title 35, U. S. Code (1952), sec. 266) This invention relates to a fuze and more particularly to a firing device for use in a point-detonating fuze adapted for use in an ordnance missile such, for example, as a projectile or the like. More specifically, the invention relates to a new and improved normally locked firing pin for a projectile in which means integrally formed thereon and responsive to impact of the missile With a target is sheared and releases the firing pin whereupon the firing pin is forcibly driven into firing engagement with the detonator supported in the arming rotor of the fuze.

An object of the invention is the provision of a new and improved shearable impact responsive firing device for a projectile fuze.

Another object is to provide a new and improved firing device for initiating explosion of an ordnance missile as the shearable means formed integrally thereon is severed therefrom in response to impact of the missile with a target.

A further object is to provide a new and improved firing device for an explosive projectile which is economical to manufacture, reliable in operation, and which possesses the qualities of durability and safety during i YAMhandling andgtransportation.

Other objects adany'of'the attendantgadvantages of this invention will be readily appreciated as'the" same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings whereas:

Fig. l is a central longitudinal section-al view of a fuze employing the firing device of the present invention according to a preferred embodiment thereof;

Fig. 2 is a View of the fuze of Fig. l, taken substantially at a right angle thereto;

Fig. 3 is a view similar to Fig. 1 showing the fuze in an armed condition; and,

Fig. 4 is .an enlarged detail view of the firing device.

Referring now to the drawings for a more complete understanding of the invention and more particularly to Fig. 1 thereof, there is shown thereon a fuze generally indicated by the reference character comprising a casing 11 composed of any material suitable for the purpose such, for example, as steel or the like.

A windshield indicated generally at 12 is secured to the casing 11 in any suitable manner preferably by crimping engagement therewith and indicated by the numeral 13, the member 12 being composed of any material suitable for the purpose such, for example, as aluminum, brass or the like.

The leading end portion of the casing 11 is provided with a well or recess 14 terminating in a restricted bore 15 in communication with a Well 16, the aforesaid leading end being disposed in spaced relation with respect to the crushable nose portion 17 of the member 12. By this arrangement a chamber 18 is formed between the leading end of the casing and the crushable nose portion 17 of the windshield 12.

Disposed within the leading end of the casing 11 and generally indicated by the reference character 19 is a 2,812,714 Patented Nov. 12, 1957 firing pin composed of a suitable metallic material such, for example, as aluminum or the like. The pin com` prises an enlarged circular head 21 arranged with the chamber 18 and well 14 and having a circular portion'. 22 formed thereon in proximate spaced relation with re-l spect to nose portion 17. Integrally formed on the head 21 and disposed substantially midway between the outer and inner surfaces thereof is a shearable flange 23, they flange being in engagement with the casing 11 as indicated by the numeral 24 in such a manner as to be sheared as, the nose 17 is crushed upon impact of the missile with a target. Formed on the head 21 and extending through well 14, bore 15 and well 16 is ya shaft 25 having formed thereon a striker 26 normally in engagement with the arming rotor generally indicated by the numeral 27 and having an annular groove 28 arranged therein. Disposed within the groove 28 in abutting engagement with the wall 29 defining the well 16 is a spring retaining ring or Washer 31 and thus by this arrangement and in conjunction with the flange 23 movement of the firing pin is prevented until the flange is severed in response to impact of the missile with a target. It will be noted that the head 21 and the shaft 25 are slidably arranged within the well 14 and bore 15 respectively, accordingly they are adapted to slide therethrough as the flange 23 is severed.

The casing 11 is provided with an enlarged bore 32, threaded as at 34 for threaded engagement with a magazine generally indicated by the numeral 35 whereupon the magazine is secured to the casing 11. Disposed within a bore 36 formed in the magazine 35 is a booster charge 37 composed of any explosive suitable for the purpose but preferably of the type known in the trade as TetryL The bore 36 terminates in an enlarged portion 38 in which is disposed a support or member 39 having a centrally disposed bore 41 arranged therein for supporting a lead-in charge 42, Figs. 1 and 3, the lead-in charge being in abutting engagement with the booster charge 37. Thus when the lead-in charge is fired the booster charge is fired thereby. It will be understood, however, Vthat the lead-in charge is adapted to be fired by the detonator 43 arranged in the arming rotor 27 when the arming rotor is in an armed position, Fig. 3, and the firing pin 25 is forcibly driven into engagement with the detonator in response to impact of the missile with the target.

The arming rotor may be of any conventional type Stich, for example, as the type disclosed and claimed in the copending application of R. L. Graumann, for a Projectile Fuze, Serial No. 596,068, filed May 26, 1945 which has matured into United States Patent Number 2,741,183 on April l0, 1956. The arming rotor 27' will be maintained in a safe position with the firing pin 25 out of alignment with the detonator 43 and the detonator out of alignment with the lead-in charge by a pin 44 and a setback block 45 slideably ranged in the casing 11 pin 44. When the pin setback force received projectile is red from the gun the rotor is released.` When this occurs and the setback force has and `secured to the rotor by the 44 is sheared in response to the will be moved to an armed position Fig. 3, when the pro-- jectile has reached a maximum speed of rotation andi thus the detonator is brought into alignment with the: firing pin and the lead-in charge.

Upon impact of the projectile with the target the firing pin 25 is `forcibly driven inwardly as the nose of the windshield is crushed into engagement with the portion 22 thereof, the force of the impact being sufficient tocause the flange 23 to be sheared from the head 22 as the head moves inwardly and the flange is impinged by the shoulder 24. Thus in response to the movement of disposed in a slot 40 ar by the setback block 45 as thedecayedA sufficiently to permit free rotation of the rotor, the rotor` 3 the tiring pin after shearing of the flange the striker 26 thereon is forcibly driven into tiring engagement with the detonator 43.

When this occurs the detonator fi'res the lead-in charge Q2 which in turn fires the booster charge 37 and thus initiating the explosion of the missile on the target. However, if desired, a suitable delay element may be employed for delaying the explosion of the missile for a predetermined period of time after impact thereof with the target. Y

From the foregoing, it will be apparent that a novel firing device has been provided for a projectile which possesses the essential characteristics of safety during firing, handling and transportation Without'the use of numerous safety devices heretofore employed for locking the firing pin in a safe position such, for example, as the conventional centri ugally actuated spring locking detents.

Furthermore, from the foregoing, it will be apparent that the present invention provides a novel firing device for initiating explosion of a projectile as the dnctile flange integrally formed thereon is sheared in response to im'- pact of the projectile with a target and which is economical to manufacture, reliable in operation and which possesses the qualities of durability and safety.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. lt is therefore to be understood that Within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

r'ne invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes Without the payment of any royalties thereon or therefor.

What is claimed as new and ldesired to be secured by Letters Patent of the United States is:

An impact responsive ordnance `fuze comprising a fuze body having formed therein an open-ended'axial bore of which an intermediate portion thereof is of constricted cross-section to partition said bore into communicating upper and lower end bore portions, said intermediate portion defining a transverse surface in face adjacency to said 2,812,714 f I Y Y 4 lower end portion, a tiring pin member slideably dis` posed Within said bore, said member including an enlarged hemispheroidal head and an elongated shaft integrally formed thereon, a shearable ange formed on said enlarged head and normally engaging a shoulder formed on said fuze body at the remote extent of said upper end portion, an annular recess `formed on said shaft, a spring retaining ring conformingly seated in said recess and normally in abutting engagement with said transverse surface, said ring and said flange cooperating to releasably secure said firing pin member Within said axial bore, an arming rotor rotatably supported within said fuze body in an initial safe position with respect to said Vtiring pin member, a detonator Varranged in said arming rotor, inertial means arranged Within said fuze body and responsive to setback force for releasably locking said rotor in said initial safe position and for releasing said rotor for rotation t0 .an armed position with respect to said tiring pin member when tne fuze is subjectedr to setback force, and a nose cap aixed to the fuze body and configured to *formY a hemispheroidal vertex portion spatially enclosing said enlarged head, said cap being constructed of a crushable material capable of being driven into force-imparting engagement with said enlarged head upon impact of the fuze with a target, thereby to sever sai-d shearable means and drive said tiring pin member into engagement with said detonator.

References Cited in the le of this patent UNITED STATES. PATENTS 

